console.log("hello world");

setTimeout(() => {
    console.log('定时器内容');
}, 1000);

setInterval(() => {
    console.log("循环定时器");
}, 1000);

// console.log(window); //ReferenceError: window is not defined

// let window = '123';
// console.log(window);

console.log(global); //node 的全局对象
